LAKE FOREST – When John Fox says an injury is serious, that’s usually time to worry.

After all the coach is usually not willing to tip his hand as to whether a player’s ailment is one that will keep him out for a little or a lot of time. But on Sunday the Bears head coach was quick to call the right knee injury of linebacker Danny Trevathan “serious.”

On Monday his fears were confirmed as Trevathan was diagnosed with ruptured patellar tendon in his right knee and will be out for the rest of the season after being placed on injured reserve.

The injury occurred in the final three minutes of the Bears’ 27-21 loss to the Titans. Trevathan fell to the ground going for a tackle in the backfield and had to be helped off the field by athletic trainers.

His injury is the second of the linebacker’s first season with the Bears. Back in week two Trevathan injured his thumb and underwent surgery that kept him out for almost a month.

Signed away from the Broncos in the offseason, Trevathan finished 2016 with 66 tackles along with a sack and four pass deflections in nine games.